• Title/Summary/Keyword: SURF

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Arctic Sea Ice Motion Measurement Using Time-Series High-Resolution Optical Satellite Images and Feature Tracking Techniques (고해상도 시계열 광학 위성 영상과 특징점 추적 기법을 이용한 북극해 해빙 이동 탐지)

  • Hyun, Chang-Uk;Kim, Hyun-cheol
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1215-1227
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    • 2018
  • Sea ice motion is an important factor for assessing change of sea ice because the motion affects to not only regional distribution of sea ice but also new ice growth and thickness of ice. This study presents an application of multi-temporal high-resolution optical satellites images obtained from Korea Multi-Purpose Satellite-2 (KOMPSAT-2) and Korea Multi-Purpose Satellite-3 (KOMPSAT-3) to measure sea ice motion using SIFT (Scale-Invariant Feature Transform), SURF (Speeded Up Robust Features) and ORB (Oriented FAST and Rotated BRIEF) feature tracking techniques. In order to use satellite images from two different sensors, spatial and radiometric resolution were adjusted during pre-processing steps, and then the feature tracking techniques were applied to the pre-processed images. The matched features extracted from the SIFT showed even distribution across whole image, however the matched features extracted from the SURF showed condensed distribution of features around boundary between ice and ocean, and this regionally biased distribution became more prominent in the matched features extracted from the ORB. The processing time of the feature tracking was decreased in order of SIFT, SURF and ORB techniques. Although number of the matched features from the ORB was decreased as 59.8% compared with the result from the SIFT, the processing time was decreased as 8.7% compared with the result from the SIFT, therefore the ORB technique is more suitable for fast measurement of sea ice motion.

Numerical Analysis of Runup and Wave Force Acting on Coastal Revetment and Onshore Structure due to Tsunami (해안안벽과 육상구조물에서 지진해일파의 처오름 및 작용파력에 관한 수치해석)

  • Lee, Kwang Ho;Kim, Chang Hoon;Kim, Do Sam;Yeh, Harry;Hwang, Young Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.289-301
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    • 2009
  • In this work, wave run-up heights and resultant wave forces on a vertical revetment due to tsunami (solitary wave) are investigated numerically using a numerical wave tank model called CADMAS-SURF (CDIT, 2001. Research and Development of Numerical Wave Channel (CADMAS-SURF). CDIT library, No. 12, Japan.), which is based on a 2-D Navier-Stokes solver, coupled to a volume of fluid (VOF) method. The third order approximate solution (Fenton, 1972. A ninth-order solution for the solitary wave. J. of Fluid Mech., Vol. 53, No.2, pp.257-271) is used to generate solitary waves and implemented in original CADMAS-SURF code. Numerical results of the wave profiles and forces are in good agreements with available experimental data. Using the numerical results, the regression curves determined from the least-square analysis are proposed, which can be used to determine the maximum wave run-up height and force on a vertical revetment due to tsunami. In addition, the capability of CADMAS-SURF is demonstrated for tsunami wave forces acting on an onshore structure using various configuration computations including the variations of the crown heights of the vertical wall and the position of the onshore structure. Based on the numerical results such as water level, velocity field and wave force, the direct effects of tsunami on an onshore structure are discussed.

Effects of Coastal Groundwater Level on Beach Deformation (해안지하수위가 해빈변형에 미치는 영향)

  • Lee, Woo-Dong;Hur, Dong-Soo
    • Journal of Ocean Engineering and Technology
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    • v.33 no.6
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    • pp.581-589
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    • 2019
  • In order to understand the characteristics of beach deformation, in this study, numerical simulations were conducted using a 3-D hydro-morphodynamic model (HYMO-WASS-3D) to analyze the characteristics of beach deformation due to the coastal groundwater levels. HYMO-WASS-3D directly analyzed the nonlinear interaction between the hydrodynamic and morphodynamic processes in the coastal area. The simulation results of HYMO-WASS-3D showed good agreement with the experimental results on the changes in the profile of the beach in the surf and swash zones. Then, numerical simulations were conducted to examine the characteristics of beach deformation due to the variation of the level of the coastal groundwater. As a result, the beach profiles were examined in relation to the wave breaking in the surf zone and the wave uprush and backwash in the swash zone due to the differences in the water levels. This paper also discussed the temporal and spatial distributions of the velocities, vorticities, and suspended sediments in the surf and swash zones with various levels of the coastal groundwater.

Feature Matching Algorithm Robust To Noise (잡음에 강인한 특징점 정합 기법)

  • Jung, Hyunjo;Yoo, Jisang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2015.07a
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    • pp.9-12
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    • 2015
  • In this paper, we propose a new feature matching algorithm by modifying and combining the FAST(Features from Accelerated Segment Test) feature detector and SURF feature descriptor which is robust to the distortion of the given image. Scale space is generated to consider the variation of the scale and determine the candidate of features in the image robust to the noise. The original FAST algorithm results in many feature points along edges. To solve this problem, we apply the principal curvatures for refining it. We also use SURF descriptor to make it robust against the variations in the image by rotation. Through the experiments, it is shown that the proposed algorithm has better performance than the conventional feature matching algorithms even though it has much less computational load. Especially, it shows a strength for noisy images.

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ROI Based Real Time Image Stitching Using the Directionality of the Image (영상의 방향성을 이용한 ROI 기반 실시간 파노라마 영상 정합)

  • Nam, Ki-Hun;Choi, Se-Jin
    • Journal of IKEEE
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    • v.20 no.4
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    • pp.420-423
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    • 2016
  • In this paper, we proposed an implementation of panoramic image stitching that operates in real time at the embedded environment by applying ROI based PROSAC algorithm using the directionality of the image. The conventional panoramic image stitching applies SURF or SIFT algorithm which contains unnecessary computation and a lots of data to detect feature points. In this paper, we use the direction of the input image and we proposed the method of reducing the unnecessary computation by using ROI. We use a gyro sensor and an acceleration sensor. Output data from gyro and acceleration sensors can be calibrated by complementary filter. The calibration does not affect the operating time of the proposed image stitching algorithm in embedded environment. Therefore, it is possible to operate in real-time.

An Approach on the Scheme Interactive of Electronic Trade Payment System Type (전자무역결제 유형의 제도적 상호관계성에 따른 접근방안)

  • Lee, Je-Hong
    • International Commerce and Information Review
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    • v.9 no.1
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    • pp.149-168
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    • 2007
  • e-Trade Payment system has been transformed by quickly and effectively. The e-trade Payment system such as TradeCard System, Bolero Surf, Identrus Eleanor and e-Escrow and e-letter of Credit issued by SWIFT System enable partly sellers, buyers and service providers. This paper studies for SWIFT, Surf, TradeCard, Eleanor, e-Escrow as international trade payment, As reason following : The First, Bolero is a neutral secure platform enabling paperless trading between exporter, importer, and their logistics service and bank partners, insurance company. The Second, TradeCard is to manage procurement-to-payment worldwide, that is exporter, importer and connected partners, paperless platform. The Third, Identrus is the global leader in trusted identity solutions, recognized by global financial institutions, commercial organizations and bank partners around the world. The Forth, Escrow payment have effect to L/C issue and enter into electronic contracts in internet bank. Trader practice use Escrow Bank as the same bank that rules to Issuing Bank and Advising Bank and payment, acceptance. This paper of these electronic payment have studies new international trade payment to approach such as eUCP rules and TradeCard System, Surf of bolero, eleanor of Identrus, SWIFT.

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Implementation of augmented reality using parallel structure (병렬구조를 이용한 증강현실 구현)

  • Park, Tae-Ryong;Heo, Hoon;Kwak, Jae-Chang
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.371-377
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    • 2013
  • This thesis propose an efficient parallel structure method for implementing a FAST and BRIEF algorithm based Augmented Reality. SURF algorithm that is well known in the object recognition algorithms is robust in object recognition. However, there is a disadvantage for real time operation because, SURF implementation requires a lot of computation. Therefore, we used a FAST and BRIEF algorithm for object recognition, and we improved Conventional Parallel Structure based on OpenMP Library. As a result, it achieves a 70%~100% improvement in execution time on the embedded system.

Moving Object Detection Using SURF and Label Cluster Update in Active Camera (SURF와 Label Cluster를 이용한 이동형 카메라에서 동적물체 추출)

  • Jung, Yong-Han;Park, Eun-Soo;Lee, Hyung-Ho;Wang, De-Chang;Huh, Uk-Youl;Kim, Hak-Il
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.1
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    • pp.35-41
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    • 2012
  • This paper proposes a moving object detection algorithm for active camera system that can be applied to mobile robot and intelligent surveillance system. Most of moving object detection algorithms based on a stationary camera system. These algorithms used fixed surveillance system that does not consider the motion of the background or robot tracking system that track pre-learned object. Unlike the stationary camera system, the active camera system has a problem that is difficult to extract the moving object due to the error occurred by the movement of camera. In order to overcome this problem, the motion of the camera was compensated by using SURF and Pseudo Perspective model, and then the moving object is extracted efficiently using stochastic Label Cluster transport model. This method is possible to detect moving object because that minimizes effect of the background movement. Our approach proves robust and effective in terms of moving object detection in active camera system.

Changes in Taste Compounds of Processed Surf Clam(Mactra veneriformis) (동죽(Mactra veneriformis)가공에 따른 정미성분의 변화)

  • Ryu, Hwa-Jeong;Ko, Young-Su
    • Korean Journal of Food Science and Technology
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    • v.17 no.3
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    • pp.223-226
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    • 1985
  • The taste compounds including glycogen, nucleotides and their related compounds and free amino acid content of Raw, Boiled and Sun-dried and Boided and 1lot-air dried surf clam(Mactra veneriformis) were investigated. Crude protein and crude lipid content changed little after processing, but ash content of processed surf clam was increased 21.5%. Glycogen content was increased 6.7% in a processed surf clam. In nucleotides and their related compounds there are much ATP, ADP, IMP and Hypoxannthine in raw material, ATP, ADP, IMP content was decreased and Hypoxannthine disappeared after processing, In the raw extract, glycine, alanine, arginine were abundant, holding 85% of total free amino acid contents. After processing, generally 60% of raw material free amino acids content were existed.

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Color balancing of the half-mirror-based stereo image by using SURF algorithm (SURF 알고리즘을 이용한 직교식 스테레오 카메라 영상의 칼라 불균형 보정 방법)

  • Li, Ruei-Hung;Shin, Hyoungchul;Sohn, Kwanghoon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.11a
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    • pp.133-136
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    • 2011
  • 본 논문에서는 SURF 알고리즘을 이용한 직교식 스테레오 카메라 영상의 칼라 불균형 보정 방법 제안한다. 제안 방법에서는 SURF 알고리즘을 이용하여 스테레오 좌, 우 영상의 대응점을 찾은 후, 찾은 대응점들의 칼라 보정 벡터를 영상 획득 모델을 기반으로 계산한다. 영상 전체에서 다양한 칼라 대응점 정보를 추출하기 위하여 본 논문에서는 분할영상을 이용하여 칼라 대응점 정보를 추출한다. 추출된 대응점 정보는 초기 칼라 보정 벡터로 변환할 수 있으며 좌, 우 영상의 모든 픽셀에 대하여 색정보가 가장 유사한 대응점의 보정 벡터를 사용하여 칼라 불균형을 보정한다. 초기 보정 벡터를 이용한 칼라 불균형 보정 후 존재하는 노이즈을 제거하기 위하여 유사한 색공간에 위치한 칼라 보정 벡터에 가우시안 필터를 적용한다. 실험 결과로 원본 영상과 보정된 영상의 칼라 히스토그램을 비교하였으며, 분할 영역의 수에 따른 보정 결과도 비교 제시하였다. 실험 결과는 제안한 방법이 직교식 스테레오 카메라 영상에 효과적인 칼라 불균형 보정 방법임을 보여준다.

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